Step 1: Preheat the oven to 350°F/180°C.
Step 2: Grease the mold and place butter paper in the bottom and flour.
Step 3: In a bowl, sift the flour together with the baking soda, salt and cocoa (cocoa powder) and reserve.
Step 4: In another bowl, mix the eggs together with the oil, buttermilk and vanilla.
Step 5: Add the dry ingredients in two batches and mix with enveloping movements.
Step 6: Add the sugar and mix well until integrated.
Step 7: Place the dough in the mold and bake for 25 minutes, until when inserting a tester, it comes out clean.
Step 8: Let cool for about 10 minutes in the pan, then turn out onto a wire rack and let them cool completely.
Step 9: Chop the top and open a hole with a spoon.